Centre and surround influences on the proximal negative response of the pigeon retina

Abstract

1. Extracellular field potentials were recorded with micro‐electrodes in the inner plexiform layer of the pigeon retina. Stimulus patterns were projected on a tangent screen. 2. Maximal responses to a 1° spot were produced from a receptive area 2–3° in extent. Annuli centred over this area produced a different response wave form. 3. The responses to centred spots and annuli presented synchronously do not superpose: they interact in a way suggesting transient mutual antagonism. The response to spot onset and offset can be suppressed either by annulus onset or by annulus offset. 4. A steady annulus has little effect on the response to spot stimuli, but a steady centred spot enhances the response to annular stimulation. 5. The results suggest that the PNR results from convergence of on‐centre and off‐centre pathways, which are embedded in a widespread suppressive surround.